Lattice GPON Solution
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In a GPON system, each user is given a timeslot on which data can be transmitted. The usage of dark fiber means that upstream traffic (from ONU to OLT) is not continuous, but composed of BURSTS. Therefore, a Burst Mode Receiver (BMR) is required.
Lock times for these BMRs tend to be very short (50 bit times for GPON), whereas traditional XAUI or SONET based SERDES have very long lock times (thousands of bit times). Customers have therefore to revert to specialized discrete BMRs that tend to expend a lot power, and lead to non-optimized footprint and system cost.
The LatticeSC, with the unique INDEL and AIL capabilities built into its PURESPEED I/O buffers, offers a fast locking, low latency receiver that works all the way up to 2Gbps data rates.
The Lattice BM reference Design Features
- Receive Frame Termination: Preamble detection and delimiter logic
- Transmit Framer Encapsulation: Header Insertion
- AIL Setup: ORCAstra GUI module with GPON settings
A demonstration platform is also available with this reference design that emulates:
- Generation of bursty random length packets with varying dead time
- PRBS generator/Checker
- Randomized clock phase delta to emulate multiple ONUs